Nature of Operations and Summary of Significant Accounting Policies Nature of Operations and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation. The accompanying unaudited Consolidated Financial Statements were prepared in accordance with GAAP and the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Corporation’s Consolidated Financial Statements and footnotes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2017.
Principles of Consolidation	The unaudited Consolidated Financial Statements include the accounts of the Corporation and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. In accordance with the provisions of Accounting Standards Codification (“ASC”) Topic 810, the Corporation’s ownership interest in FBFS Statutory Trust II (“Trust II”) has not been consolidated into the financial statements.
Use of Estimates	Management of the Corporation is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements as well as reported amounts of revenues and expenses during the reporting period. Actual results could differ significantly from those estimates. Material estimates that could significantly change in the near-term include the value of securities and interest rate swaps, level of the allowance for loan and lease losses, lease residuals, property under operating leases, goodwill, level of the Small Business Administration (“SBA”) recourse reserve and income taxes.
Reclassification	Certain amounts in prior periods may have been reclassified to conform to the current presentation
Subsequent Events	Subsequent events have been evaluated through the date of the issuance of the unaudited Consolidated Financial Statements. No significant subsequent events have occurred through this date requiring adjustment to the financial statements or disclosures.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” with an original effective date for annual reporting periods beginning after December 15, 2016. The ASU is a converged standard between the FASB and the IASB that provides a single comprehensive revenue recognition model for all contracts with customers across transactions and industries. The primary objective of the ASU is revenue recognition that represents the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU 2014-09 to annual and interim reporting periods in fiscal years beginning after December 15, 2017. In March 2016, the FASB issued ASU No. 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net).” The ASU intends to improve the operability and understandability of the implementation guidance of ASU 2014-09 on principal versus agent considerations. In April, May and December 2016, the FASB also issued ASU No. 2016-10, No. 2016-12 and No. 2016-20, respectively, related to Topic 606. The amendments do not change the core principles of the previously issued guidance, but instead further clarify and provide implementation guidance for certain aspects of the original ASU. During the first quarter of 2018, the Company adopted ASU 2014-09 and all subsequent amendments to the ASU (collectively, “ASC 606”) using the modified retrospective method. The majority of the Company’s revenues are derived from interest income and other sources that are outside the scope of ASC 606. The primary revenue streams subject to the guidance include trust and investment services fee income, service charges on deposits and the sale of foreclosed properties. The Corporation completed an assessment and evaluated contracts to assess and quantify accounting methodology changes resulting from these standards. Trust and investment service fees: The Corporation earns fees from contracts with customers for investment management, trust and estate management, company retirement plan and brokerage services to manage assets for investment and/or transact on their accounts. These fees are primarily earned over time as the Corporation provides the contracted monthly, quarterly or annual services and are generally assessed based on a tiered scale of the market value of assets under management or administration at the end of the period. Fees that are transaction-based are recognized at the point in time that the transaction is executed. Service charges on deposits: The Corporation earns fees from deposit customers for account maintenance, information reporting, account reconciliation and transaction-based activity, such as overdraft and service fees. Transaction-based fees are recognized at the time the transaction is executed as that is the point in time the Corporation fulfills the customer’s request. All other fees are earned over the course of a month, representing the period over which the Corporation satisfies the performance obligation. Gain or loss on foreclosed properties: The Corporation records a gain or loss from the sale of foreclosed property when control of the property transfers to the buyer. If the Corporation finances the sale of the property to the buyer, the Corporation assesses whether the buyer is committed to perform their obligations under the contract and whether collectability of the transaction price is probable. Once these criteria are met, the foreclosed property is derecognized and the gain or loss on sale is recorded upon the transfer of control of the property to the buyer. In determining the gain or loss on the sale, the Corporation adjusts the transaction price and related gain or loss on sale if a significant financing component is present. The adoption of ASC 606 did not result in a change to the current accounting practices for any of the in-scope revenue streams; as such, no cumulative effect adjustment was recorded. In January 2016, the FASB issued ASU No. 2016-01, “Financial Instruments (Subtopic 825-10).” The ASU amends certain aspects of recognition, measurement, presentation and disclosure of financial instruments. This amendment supersedes the guidance to classify equity securities with readily determinable fair values into different categories, requires equity securities to be measured at fair value with changes in the fair value recognized through net income and simplifies the impairment assessment of equity investments without readily determinable fair values. The amendment requires public business entities that are required to disclose the fair value of financial instruments measured at amortized cost on the balance sheet to measure that fair value using the exit price notion. The amendment requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option. The amendment requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or in the accompanying notes to the financial statements. The amendment reduces diversity in current practice by clarifying that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available for sale securities in combination with the entity’s other deferred tax assets. This amendment is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Entities should apply the amendment by means of a cumulative-effect adjustment as of the beginning of the fiscal year of adoption, with the exception of the amendment related to equity securities without readily determinable fair values, which should be applied prospectively to equity investments that exist as of the date of adoption. The Corporation adopted the accounting standard during the first quarter of 2018 and modified its fair value disclosure of financial instruments to reflect an exit price notion. The modifications were substantially related to loans and lease receivables, deposits, Federal Home Loan Bank advances and other borrowings. The Corporation did not have any equity securities subject to the fair value adjustment. The adoption of the standard did not have a material impact on the Corporation’s results of operations, financial position and liquidity. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” The ASU intends to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities and disclosing key information about leasing arrangements. The ASU will require lessees to recognize the following for all leases (with the exception of short-term leases) at the commencement date: (1) a lease liability, which is a lessees’ obligation to make lease payments arising from a lease, measured on a discounted basis; and (2) a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. Under the new guidance, lessor accounting is largely unchanged. Certain targeted improvements were made to align, where necessary, lessor accounting with the lessee accounting model and Topic 606, Revenue from Contracts with Customers. The new lease guidance simplifies the accounting for sale and leaseback transactions primarily because lessees must recognize lease assets and lease liabilities. Lessees (for capital and operating leases) and lessors (for sales-type, direct financing, and operating leases) must apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The modified retrospective approach would not require any transition accounting for leases that expired before the earliest comparative period presented. The ASU is effective for public companies for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. The Corporation intends to adopt the accounting standard during the first quarter of 2019, as required, and is currently evaluating the impact on its results of operations, financial position and liquidity. The Corporation leases office space, loan production offices and specialty financing production offices under noncancelable operating leases which expire on various dates through 2029. The Corporation also leases office equipment. Future minimum lease payments for noncancelable operating leases as of March 31, 2018 was $12.0 million. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments- Credit Losses (Topic 326).” The ASU replaces the incurred loss impairment methodology for recognizing credit losses with a methodology that reflects all expected credit losses. The ASU also requires consideration of a broader range of information to inform credit loss estimates, including such factors as past events, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. The amendments affect loans, debt securities, trade receivables, net investments in leases, off-balance-sheet credit exposures and any other financial asset not excluded from the scope that have the contractual right to receive cash. Entities will apply the amendments in the ASU through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The ASU is effective for public companies for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted as of the fiscal years beginning after December 15, 2018. The Corporation intends to adopt the accounting standard during the first quarter of 2020, as required, and is currently evaluating the impact on its results of operations, financial position and liquidity. A cross-functional team has been established and a third-party software solution has been obtained to assist with the implementation of the standard. Management is in the process of gathering necessary data and reviewing potential methods to calculate the expected credit losses. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230).” The ASU provides guidance on eight specific cash flow issues with the objective of reducing diversity in practice. The ASU is effective for public companies for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. The amendments in this update will be applied retrospectively to each prior period presented. The Corporation adopted the accounting standard during the first quarter of 2018 with no material impact on its results of operations, financial position and liquidity. In May 2017, the FASB issued ASU No. 2017-09, “Compensation- Stock Compensation (Topic 718).” The ASU provides clarity about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting. The ASU is effective for all entities for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. The Corporation adopted the standard in the first quarter of 2018 with no material impact on its results of operations, financial position and liquidity. In February 2018, the FASB issued ASU No. 2018-02, “Income Statement- Reporting Comprehensive Income (Topic 220).” The ASU allowed a reclassification from accumulated comprehensive income to retained earnings for stranded effects resulting from the Tax Cuts and Jobs Act. The ASU is effective for all entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. The Corporation early adopted the standard in the fourth quarter of 2017, which resulted in a $222,000 one-time reclassification from accumulated comprehensive income to retained earnings.